Telecommunications System

ABSTRACT

In a telecommunications system such as a global mobile telephone network in which each subscriber unit includes a Subscriber Identity Module (SIM card), each SIM card has fixed memory locations, to which data can be addressed over the air. Some of the locations can not be overwritten from the subscriber unit but can be accessed therefrom on the entry of short simple codes, each associated with one of the locations. Further fixed memory locations can be read over the air only when the subscriber enters a personal identification number. Locking control files are used to control read/write access to the locations respectively.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.09/455,628, filed Dec. 7, 1999, which is assigned to the same assigneeas the present application, is incorporated herein by reference and is acontinuation of U.S. patent application Ser. No. 08/557,147, filed Apr.19, 1996, now U.S. Pat. No. 6,011,976, which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

This invention relates to a telecommunications system. In particular,but not exclusively, it relates to a mobile communications system suchas a cellular mobile radio or telephone system.

A recent innovation in such systems has been the introduction ofSubscriber Identity Modules (SIM cards). These are integrated circuitcards which can be releasably inserted into a mobile telephone and whichcontain in memory the subscriber's identity, i.e., his telephone number.These known SIM cards also have a rolling buffer which can store acertain number of alphanumeric characters. The buffer facilitates theso-called Short Message Service (SMS) in which a message for asubscriber or for a specified group of subscribers can be broadcast overthe air, as an advanced form of radiopaging. Messages can be received bya mobile telephone whenever it is idle or on stand-by. However, if amessage is received which would overfill the buffer, data is lost on afirst-in-first-out basis.

It is an object of the invention to provide a more efficient andremotely reconfigurable SIM card.

SUMMARY OF THE INVENTION

From one aspect, the present invention consists in a telecommunicationssystem comprising at least one host station and a plurality ofsubscriber units, the or each host station being operable to transmit amessage to at least one of the subscriber units, and each subscriberunit having a multiplicity of fixed memory locations and meansresponsive to the detection of the message to store the message in aselected one of the fixed memory locations which can not be overwrittenfrom the subscriber unit, but which can be accessed from the subscriberunit when required.

In the present application, a “fixed” memory location means a locationinto which data can be written, and excludes first-in-first-out orcircular buffers. Overwriting of all the data in certain “fixed” memorylocations may occur in contrast to the first-in-first-out loss of dataexperienced with current SMS buffers.

Thus, for example, a set of telephone numbers, each with an identifyingalphanumeric tag, can be transmitted to the SIM card, allowing userseasy access to commonly used services such as hotels, car hire orairline reservations. This feature is known as a Value Added ServiceDirectory.

A message may be retrievable by the subscriber on the entry of simple,short codes into the subscriber unit, each memory location correspondingto a particular code. A message may include a telephone number and, oncestored, may be able to be overwritten over the air. Preferably, the oreach host station is operable to transmit a request for informationstored in a subscriber unit. The information may be included in amessage and it may also include information which is stored in a securememory location, accessible only when the subscriber enters a personalidentification number (PIN number). The information may include creditdetails relevant to the subscriber, for example, a credit card number ofcredit status, thus greatly facilitating credit card transactionscarried out over the telephone. Using this feature of the invention, acredit account holder avoids having to dictate his account details andneed only enter the mandatory PIN number.

The host station may be operable to transmit instructions to lock and/orunlock a memory location at the subscriber unit. It may be operable totransmit instructions to run a program stored in memory locations at thesubscriber unit. The host station may be operable to transmit filescontaining functional data and/or files containing non-functional datato the subscriber unit. The messages, requests for information and theinstructions being transmitted may be in a specific format which thesubscriber unit is able to distinguish from other formats. The specificformat may be made secure against interception.

In a preferred embodiment, the subscriber unit comprises a mobile radioor telephone and an integrated circuit card which can be removablyconnected to the radio/telephone. The integrated circuit card maycontain the memory locations and may contain means for distinguishingthe specific format from other formats. The card may contain means fordistinguishing between the messages, requests for information andinstructions. The card may also contain the means for storing themessages and means for acting on the requests and instructions.

From another aspect, the invention consists in a module for controllinga subscriber unit in a telecommunications system, comprising amultiplicity of fixed memory locations and means responsive to thedetection of a message transmitted remotely thereto to store the messagein a selected one of the fixed memory locations, and being adapted forremovable connection to a transceiver of the subscriber unit.

At least one of the fixed memory locations may be protected fromoverwriting by the subscriber. The module or card may include means forrendering any or all of said fixed memory locations accessible orinaccessible by either the subscriber or the host station. The card mayinclude a directory structure within which files can be stored.

The invention is particularly applicable to global telecommunicationsystems in which the mobile cellular telephone networks of variouscountries or areas communicate using a common standard. An example ofsuch a global system is GSM (Global System for Mobile Communications)currently operating in Europe. However the invention is not limited toglobal systems and could be applied to a single national cellularnetwork or even to a fixed land-linked network.

BRIEF DESCRIPTION OF THE DRAWINGS

An embodiment of the invention will now be described by way of examplewith reference to the accompanying drawings in which:

FIG. 1 shows the transmission of messages to a subscriber unit in asystem according to the invention;

FIG. 2 shows a process in which a subscriber unit transmits a messageand requested information;

FIG. 3 is a block diagram showing elements of a module shown in FIGS. 1and 2;

FIG. 4 shows details of one of the blocks shown in FIG. 3; and

FIG. 5 is a flowchart showing the operation of the module shown in FIGS.1 to 4.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates an SMS distribution path according to the invention.In the prior art, the short messages have usually been directed to asingle subscriber or a specified group of subscribers such as a salesteam.

However, GSM also supports a feature known as Cell Broadcast in whichmessages can be sent to all the subscribers in a particular area. In theembodiment of the invention illustrated, a message consists of thetelephone number of an advertiser and an alphanumeric tag to identifythe advertiser.

An operator enters the message into a terminal 1. The message is thencoded into a secure format known to applicants as an Embedded CommandStream (ECS) and sent via a modem 2 and a fixed line 3 to a local GSMswitch 4. According to its delivery address, the message is delivered toany or all of the other switches within that network, or even acrossnetworks.

The switch 4, which in this example is in the geographical area to whichthe message is to be transmitted, delivers the message to a number ofcellsites 5. The cellsites 5 are the base transceiver stations of theGSM network.

Each cellsite 5 then broadcasts the message to a group of transceiversor mobile telephones, hereinafter referred to as “mobiles”. If CellBroadcast is used, the group consists of all mobiles within thegeographical area at the time of the broadcast.

A selected mobile 6 receiving the message transmits a confirmation ofreceipt back to its respective cellsite 5. From now on, until an updatesituation, the system will not contact this mobile 6 again.

The mobile 6 recognizes the message as SMS data and passes it to a SIMcard 7, which is a small self-contained microprocessor, held in a slotin the mobile 6. The SIM card 7 in turn recognizes the ECS using specialhardware and software and stores the message in memory in such a waythat it may not be overwritten by the subscriber. Known SIM cardscontain a large number of fixed memory locations in which the subscribercan store frequently dialed numbers and corresponding alphanumeric tags.The SIM card 7 of the invention stores the message in one of theselocations, and then carries out a write protect operation. The locationsdedicated to storing write protected messages may be designated by codenumbers relating to a particular category of advertiser. Thus, forexample, car hire company telephone numbers can be stored in location01, hotel reservations in location 02 and so on.

FIG. 2 shows a call placing process in which a subscriber communicateswith an advertiser. The subscriber, remembering that the car hirecompany's number is in location 01 as shown at 8, keys in a short codecorresponding to the location, such as 01#. The mobile 6 theninterrogates the SIM card 7 to retrieve the telephone number from thelocation. The SIM card 7 provides both the number and the alphanumerictag giving the company's name and displays it to the subscriber. Theuser confirms that he wishes to proceed by pressing SEND.

Next, the mobile obtains a voice channel through which the call proceedsto the dialed number. The GSM system automatically handles intra-networkand inter-network hops. At this point the subscriber can hold a voiceconversation with the company.

Providing the correct equipment has been installed at the company, assoon as the call is answered, subscriber identity information read fromthe SIM card 7 gives the company immediate customer billing details suchas a name and address.

The SIM card 7 also contains information detailing the subscriber'scredit account. This information is held in a separate, secure memorylocation, accessible only when the subscriber enters a mandatory PINnumber, known only to himself, thus confirming that the mobile has notbeen stolen or lost. When the subscriber has confirmed his car hiredeal, he enters the PIN number into the mobile 6, requesting the creditinformation from the SIM card 7. The SIM card 7 supplies the informationand the mobile uses existing voice/data techniques to transmit theinformation to the company, in a format secure against detection byfraudsters. The sale is confirmed by the company or its equipment andthe call is terminated.

In this example, it is also possible to obtain a telephone or fax numberfrom the operator-assisted directory enquiries system without thesubscriber having to manually enter the number into the communicationsterminal which he desires to use.

To use this feature, the subscriber calls network directory enquiriesand gives the name of the person, company or service of which he wishesto ascertain the telephone number, as well as any additional informationrequested by the operator answering the call. The operator then locatesthe number, confirms it and enquires as to whether the number is to betransmitted verbally, transferred over SMS into a given memory locationof the subscriber's SIM card or both.

If the subscriber chooses a SIM update, the voice call is terminated andthe operator initiates the SMS process by entering a sequence into acomputer or pressing a dedicated button. The telephone number is thenencoded into an ECS message at the despatch center and is posted acrossthe network to the subscriber's communications terminal, which transmitsa confirmation to the despatch center. Thus, the retry mechanism, whichoperates until such a confirmation is received, is suspended.

The communications terminal recognizes the message as SMS data, passesit to the SIM card, and if capable, displays a “message received”banner. The SIM card in turn recognizes the ECS using special hardwareand software, and decodes it accordingly. The number, and any associatedalphanumeric tag, which would normally consist of the name of the personor company, are recovered together with the memory location in whichthey are intended to be stored. The number and name-tag are then writtento that location and are write-protected if requested by the subscriber,the overwrite protection being encoded into the message at source.

Subsequently, the subscriber attempts to place a call to the number inthe known memory location by keying in the memory location number. TheSIM card passes the telephone or fax number to the communicationsterminal on demand, and upon receipt of the subscriber's confirmation,the communications terminal sets up the call to the desired number.

FIG. 3 shows the electronic structure of the SIM card 7. The cardcommunicates with the mobile to which it is connected via aninput/output (I/O) manager 15, preferably using the protocol ISO 7816T=0. A filter 16 receives incoming data from the I/O manager and detectsany ECS messages from among the short messages received. The ECSmessages are sent directly to an extended erasable read only memory(E²ROM) 17, which is preferably a “flash” E²ROM. Data can also be outputfrom the E²ROM directly to the I/O manager 15. The remaining blocksshown in FIG. 3 are standard components of a SIM card.

FIG. 4 shows how the E²ROM is organized. A root directory 18 contains aSIM administration and identifier 19, a GSM directory and network data20, and a telecom directory 21.

The telecom directory in turn contains memory locations as follows:“abbreviated dial numbers” 22, “capability configuration” 23, “shortmessages” 24, “fixed dial numbers” 25, and “charging counter” 26. Eachblock represents a plurality of memory locations. The frequently dialednumbers and corresponding alphanumeric tags are stored at locations 22.

The “abbreviated dial numbers” locations 22 and the “short messages”locations 24 each have an associated locking control file 27, 28,respectively. The locking control files constitute means for read/writeprotecting and removing read/write protection from their associatedmemory locations. The locking control files 27, 28 will typically be inthe telecom directory 21 as shown, however they can be located elsewheresuch as in an administration directory.

FIG. 5 is a flowchart illustrating the operation of the SIM card 7,which uses the specially fabricated hardware and software which has beendescribed above to implement the operations illustrated. At lozenge 9,messages, requests, and instructions having ECS are distinguished fromthose without. Each of these ECS types consists of a data stream headedby a command which is one of at least four types: write commands for themessages, read commands for the requests for information, attributecommands for lock or unlock instructions and run commands forinstructions to run a program.

The command and data types are decoded at box 10 and acted on in one ofthe four paths 11-14.

Path 11 handles the write commands to store messages starting at alocation specified therein. Path 12 handles the read commands; again,the requests for information contain a location to be accessed first.Successive locations are read and the data stored in a buffer until therequired amount of data has been read. The data in the buffer is thenencoded into the ECS format and despatched from the mobile using SMS tothe calling party.

In path 13, attribute commands are used to lock or unlock specifiedmemory locations and render them accessible or inaccessible, either tocalling parties or to the subscriber. In path 14, run commands cause aprogram stored in the SIM card to be run.

The basic ECS system is expandable to up to 255 internal shell commandsof which write, read, lock/unlock and run are four examples. Thespecific protocol used for the transfer of information is not fixed andcould be ISO7816 T=0 or any other suitable protocol.

The internal shell commands are a supplement to the ability of thesystem to create external file objects within the SIM card 7. The fileobjects are of two types: Application Data File Programs (ADFP's)containing functional data which can be executed by the SIM cardprocessor and can self modify if required and Application Data Files(ADF's) containing non-functional data which does not have thesecapabilities. Existing ADF(P)'S can be modified over-the-air enablingadvanced facilities such as personalization, re-personalization ordownloadable phone book.

The SIM card 7 has a directory structure, similar to that of a computerdisk, and new ADF(P)'S can be downloaded into any directory over theair. Also over the air, directories can be created, deleted andmodified, multiple tree directory operations can be carried out andADF(P)'S that are no longer required can be deleted. The amount ofADF(P) data which can be downloaded is limited only by the size of theE²ROM memory of the card.

The invention, as described, greatly extends the applications of SIMcards. For example, using the Value Added Services Directory,subscribers can book hotels and airline seats over their mobiles quicklyand easily.

An additional advantage of this feature of the invention is that thegeographical distribution of messages to cards in a specific area suchas the South of France is facilitated. Thus advertisers can direct theirmessages to all mobile subscribers in the specific area. This, isparticularly useful when subscribers “roam” from one area to another andhave no knowledge of local services.

The directory enquiries download enables contact telephone or faxnumbers to be delivered to a subscriber's communications terminalwithout any intervention by the subscriber. The process of manuallyentering a number whilst engaged in a call to the operator is oftendangerous, especially when the subscriber is driving.

The ability of the system to download ADF(P)'S means that additionalservices can be added to the SIM card over the air while maintainingtotal compatibility with the existing cellular system. Thus the SIM cardcould acquire the functions of a credit card, passport, driving licence,car park pass, membership card and so on, becoming a multi-service card.Also, dynamically updatable services can be added which require adifferent process to be run each time a service is accessed.

Once the card has extra services on it, it can be used outside of themobile phone environment if desired as a standalone item. This can beread from or written to by a dedicated piece of hardware, such as apoint of sale machine. If desired, the new services can be deleted,however the card will never lose its mobile phone SIM capability. Inaddition, if the card has extra services, they will continue to functioneven if the subscriber has been disconnected from the mobile phonenetwork, unless otherwise desired.

Modifications are possible without departing from the scope of theinvention. For example, the SIM card can be trained only to receivemessages detailing services relevant to the subscriber's needs.

1-29. (canceled)
 30. A method for issuing a command to be executed in aprocessor of a removable module in a mobile subscriber unit forming apart of a telecommunications system that includes a host station,comprising: encoding the command in a specific format; embedding theencoded command in a message body having a predetermined format to forma command message; and outputting the command message from the hoststation.
 31. The method of claim 30, wherein said embedding includesembedding a data stream, said data stream disposed in said message bodyafter said command.
 32. The method of claim 30, wherein said outputtingincludes outputting said command message using a short message serviceformat.
 33. The method of claim 30, wherein the telecommunicationssystem, comprises: a host computer configured to output a first messagein a first predetermined format, the first message having a secondmessage embedded therein, the second message having a secondpredetermined format different from the first predetermined format; anetwork coupled to the host computer and configured to receive the firstmessage; and an interface to a mobile station coupled to the network andconfigured to receive the first message from the network.
 34. The methodof claim 33, further comprising an internetwork link coupled to thenetwork and the interface to the mobile station.
 35. The method of claim34, wherein the internetwork link includes a switch.
 36. The method ofclaim 33, wherein the second message includes a command to produce anoperation in the mobile station.
 37. (canceled)
 38. A method foroperating a mobile station, comprising the steps of: receiving a codedmessage from a first host computer, the coded message being in a firstformat and including a data item embedded therein in a second format;outputting the coded message to a SIM module, the SIM module removablycoupled to the mobile station; receiving a code from a mobile stationuser, the code corresponding to a predetermined memory location for thedata item; and outputting the code to the SIM module.
 39. The method ofclaim 38, further comprising the steps of: receiving the data item fromthe SIM module; displaying the data item to the user; and outputting thedata item to a second host computer.
 40. The method of claim 39, furthercomprising the step of receiving a predetermined personal identificationnumber from the user.
 41. The method of claim 40, wherein receiving thedata item from the SIM module is only performed if the predeterminedpersonal identification number corresponds to the predetermined memorylocation.
 42. The A method of claim 46, further comprising: receivingexecutable code from a host station, the executable code comprising theexecutable code embedded in a SMS message.
 43. The method of claim 38further comprising: receiving a personal identification number from a Xuser input device; determining whether the personal identificationnumber is valid; and outputting information to a network in a secureformat if the personal identification number is valid.
 44. The method ofclaim 43, further comprising: receiving a short code from the user inputdevice; and displaying a reference on the display.
 45. The method ofclaim 43, wherein the short code contains a file object that cancomprise at least one of functional data and non-functional data.
 46. Amethod for provisioning a smart card, comprising the steps of: receivingin a transceiver a first application code transmitted from a host via alink, the smart card being coupled to the transceiver; writing the firstapplication code from the transceiver to the smart card; and decouplingthe smart card from the transceiver.
 47. The method of claim 46, whereinthe application code is in a specific format, the specific format beingembedded in a standard message format, the specific format beingdistinguishable in the smart card from the standard message format. 48.The method of claim 46, further comprising the step of transmitting theapplication code to a wireless link.
 49. The method of claim 46, furthercomprising the step of coupling the smart card to a point of salemachine.
 50. The method of claim 46, further comprising the steps of:transmitting a second application code from a host to a link; receivingthe second application code in a transceiver from the link, the smartcard being coupled to the transceiver; and writing the secondapplication code from the transceiver to the smart card.